Method and device for selectively changing the contour of the surface of an optical lens made of glass or a glass-type material

Abstract

A method and a device are disclosed for follow-up treatment of the contour of the surface of at least one optical lens, in particular a microlens which is made of glass or a glass-type material and which has a convex lens surface delimited by a circumferential line abutting on a plane section surrounding the circumferential line and which has a lens underside facing the convex lens surface. Along the circumferential line of the optical lens on the plane section is placed a device perfectly matching the circumferential line and at least laterally bordering the convex lens surface, the optical lens is heated to a temperature of at least the transformation temperature of glass or glass-type material, pressure equalization prevails between the convex lens surface and the lens underside, after a certain period of time, during which the optical lens undergoes the temperature treatment and subsequent cooling below the transformation temperature, the device is removed from the optical lens.

1. A method for follow-up treatment of the contour of the surface of at least one as-formed convex optical lens, the method comprising:
 providing the as-formed convex optical lens which is made of glass or a glass-type material and which has a convex lens surface delimited by a circumferential line abutting on a plane section surrounding said circumferential line and which has an opposing surface of the lens facing the convex lens surface, and wherein said optical lens is produced by means of a glass-flow process or by means of contactless hot stamping of a thermoplastic material and has as a result of said process an elliptical gradient in the region of said circumferential line, 
 placing along said circumferential line of the as-formed convex optical lens on said plane section a means matching said circumferential line and at least laterally bordering said convex lens surface, 
 performing a temperature treatment comprising heating said as-formed convex optical lens to a temperature of at least the transformation temperature of said glass or glass-type material, wherein pressure equalization prevails between said convex lens surface and said opposing surface of the lens, and said temperature treatment is conducted in conjunction with said means bordering said circumferential line in such a manner that said elliptical gradient is reduced or completely eliminated, 
 removing said means from said optical lens after a period of time, during which said optical lens undergoes said temperature treatment and subsequent cooling below said transformation temperature
 wherein the steps are performed in the recited sequence and result in the modification of the elliptical gradient. 
 
 
     
     
       2. The method according to  claim 1 , wherein the temperature and the period of time of said temperature treatment are selected according to the degree of change of the surface contour. 
     
     
       3. The method according to  claim 1 , comprising varying the pressure acting on said convex lens surface during said temperature treatment. 
     
     
       4. The method according to  claim 1 , comprising pressing said means with force against said circumferential line. 
     
     
       5. The method according to  claim 1 , wherein said temperature treatment is conducted in conjunction with said means bordering said circumferential line in such a manner that the lateral geometric dimensions of said optical lens are retained. 
     
     
       6. The method according to  claim 1 , wherein the convex lens surface of said optical lens is raised above a horizontal plane during the temperature treatment. 
     
     
       7. The method according to  claim 1 , wherein said means is brought into contact with said optical lens without wetting the surface. 
     
     
       8. The method according to  claim 1 , wherein the at least one optical lens comprises a one-piece continuous array-like microlens having a multiplicity of single optical microlenses, which are spaced apart, by plane sections, a means matching the arrangement and size of the circumference of the single microlenses is provided as a template, which is placed at least partly on said plane sections and surrounds said circumferential lines of said individual microlenses, and during said temperature treatment all said microlenses are heated uniformly and homogeneously. 
     
     
       9. The method of  claim 8 , wherein the microlens are equidistantly spaced. 
     
     
       10. The method according to  claim 1 , wherein said temperature treatment occurs in such a manner that a reduction of said convex lens surface stems solely from the surface tensions acting along said convex lens surface, with the lens material being forced out of the regions of said elliptical gradient on the convex-side into other regions of the lens body. 
     
     
       11. The method of  claim 1 , wherein the optical lens is a microlens. 
     
     
       12. The method of  claim 1 , wherein the contour comprises a pre-existing elliptical gradient at an edge region of the at least one optical lens.